He donated one month of his salary, Tunisia's state news agency TAP reported.

The president also urged Tunisians at home and abroad to make donations "in support of military and security institutions well as the national efforts to combat terrorism", according to the agency.

In a separate statement on the same day, Prime Minister Habib Essid "invited members of government and high-ranking state officials to donate a day's work" to the fund.

The prime minister asked state employees and citizens "to support the national effort in the fight against the plague of terrorism".

Security forces attacked

On Monday, fighters launched a wave of attacks on army and police posts in the border town of Ben Guerdane in southeast Tunisia.

The assault and ensuing clashes around the town have killed 49 fighters, 13 members of the security forces and seven civilians, according to the AFP news agency.

There has been no claim of responsibility for the attacks, but the authorities have blamed them on the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group present in neighbouring Libya.

ISIL has taken advantage of a power vacuum in Libya since the NATO-backed overthrow of President Moammar Gaddafi in 2011 and set up bases in several areas, including near Sabratha close to the Tunisian border.

Tunisia has built a 200km barrier that stretches about half the length of its border in an attempt to stop fighter incursions from Libya.

Last year, ISIL claimed three bomb and shooting attacks in Tunisia, killing dozens of foreign tourists and presidential guards.